BJ74 A/C low vs high charging ports...

[_Walker_]

Hey all, so wanting to refill the old BJ74's A/C and was considering doing it DIY with a recharge kit. I'm a little new to A/C and after looking through the manual I can't seem to identify which one of the two charging ports is the low pressure and high pressure side...
One port is facing forward towards the belts (which I am assuming is the high side, because high side is supposed to be recharged with the engine stopped??)
And I'm assuming the low side is the one facing back.... However, If I get this wrong I'm concerned about a mess/breaking things.

Anyone have suggestions?
Also I was planning on recharging from the low side, Is it bad to do that with just a few compressed cans or should it REALLY be done with a proper vacuum system?

thanks

 

[NoGood]

The low pressure side is only low when the A/C is on. The system evens out when it is not in operation. If you are charging while the A/C is running the low pressure side will be the port you have to recharge by, but you have to be careful to not liquid slug the compressor. If liquid hits the compressor it can cause the compressor to mechanically fail, creating a much larger issue.

Also A/C should NEVER have to be recharged. It’s a closed system and if it isn’t working properly it either has a leak that should be fixed or one of the coils needs to be cleaned because it isn’t transferring heat properly.

 

[CharlesHS]

Hey all, so wanting to refill the old BJ74's A/C and was considering doing it DIY with a recharge kit. I'm a little new to A/C and after looking through the manual I can't seem to identify which one of the two charging ports is the low pressure and high pressure side...
One port is facing forward towards the belts (which I am assuming is the high side, because high side is supposed to be recharged with the engine stopped??)
And I'm assuming the low side is the one facing back.... However, If I get this wrong I'm concerned about a mess/breaking things.

Anyone have suggestions?
Also I was planning on recharging from the low side, Is it bad to do that with just a few compressed cans or should it REALLY be done with a proper vacuum system?

thanks

To confirm the locations of the low and high pressure charging ports; you can trace the lines attached to the compressor. The line that goes to the coil in front of the radiator is the high pressure line and the line that comes from the firewall is the low pressure line.
The associated charging port should be easy to confirm; there may even be a small L or H next to the charging port.
Your year LC more than likely is charged or was charged with R12; I am not sure if you are looking to convert from R12 to R134a.
If you system is charged with R12; you may find it difficult to locate R12 and you should consider converting the system to R134a which will require evacuating the system and replacing the compressor oil with PAG.
Hope this explanation answers your questions.

 

[UltraFJ40]

To confirm the locations of the low and high pressure charging ports; you can trace the lines attached to the compressor. The line that goes to the coil in front of the radiator is the high pressure line and the line that comes from the firewall is the low pressure line.
The associated charging port should be easy to confirm; there may even be a small L or H next to the charging port.
Your year LC more than likely is charged or was charged with R12; I am not sure if you are looking to convert from R12 to R134a.
If you system is charged with R12; you may find it difficult to locate R12 and you should consider converting the system to R134a which will require evacuating the system and replacing the compressor oil with PAG.
Hope this explanation answers your questions.

Good explanation. Salamat po.

 

[CharlesHS]

Glad I could help.
Walang anuman...